.\"
.\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for
.\" permission to reproduce portions of its copyrighted documentation.
.\" Original documentation from The Open Group can be obtained online at
.\" http://www.opengroup.org/bookstore/.
.\"
.\" The Institute of Electrical and Electronics Engineers and The Open
.\" Group, have given us permission to reprint portions of their
.\" documentation.
.\"
.\" In the following statement, the phrase ``this text'' refers to portions
.\" of the system documentation.
.\"
.\" Portions of this text are reprinted and reproduced in electronic form
.\" in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
.\" Standard for Information Technology -- Portable Operating System
.\" Interface (POSIX), The Open Group Base Specifications Issue 6,
.\" Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
.\" Engineers, Inc and The Open Group.  In the event of any discrepancy
.\" between these versions and the original IEEE and The Open Group
.\" Standard, the original IEEE and The Open Group Standard is the referee
.\" document.  The original Standard can be obtained online at
.\" http://www.opengroup.org/unix/online.html.
.\"
.\" This notice shall appear on any product containing this material.
.\"
.\" The contents of this file are subject to the terms of the
.\" Common Development and Distribution License (the "License").
.\" You may not use this file except in compliance with the License.
.\"
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
.\" or http://www.opensolaris.org/os/licensing.
.\" See the License for the specific language governing permissions
.\" and limitations under the License.
.\"
.\" When distributing Covered Code, include this CDDL HEADER in each
.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
.\" If applicable, add the following below this CDDL HEADER, with the
.\" fields enclosed by brackets "[]" replaced with your own identifying
.\" information: Portions Copyright [yyyy] [name of copyright owner]
.\"
.\"
.\" Copyright (c) 2001, The IEEE and The Open Group.  All Rights Reserved.
.\" Portions Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.
.\"
.TH PTHREAD_MUTEX_TIMEDLOCK 3C "Jun 5, 2007"
.SH NAME
pthread_mutex_timedlock, pthread_mutex_reltimedlock_np \- lock a mutex
.SH SYNOPSIS
.LP
.nf
cc \fB-mt\fR [ \fIflag\fR... ] \fIfile\fR... [ \fIlibrary\fR... ]
#include <pthread.h>
#include <time.h>

\fBint\fR \fBpthread_mutex_timedlock\fR(\fBpthread_mutex_t *restrict\fR \fImutex\fR,
     \fBconst struct timespec *restrict\fR \fIabs_timeout\fR);
.fi

.LP
.nf
\fBint\fR \fBpthread_mutex_reltimedlock_np\fR(\fBpthread_mutex_t *restrict\fR \fImutex\fR,
     \fBconst struct timespec *restrict\fR \fIrel_timeout\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBpthread_mutex_timedlock()\fR function locks the mutex object referenced
by \fImutex\fR. If the mutex is already locked, the calling thread blocks until
the mutex becomes available as in the \fBpthread_mutex_lock\fR(3C). If the
mutex cannot be locked without waiting for another thread to unlock the mutex,
this wait is terminated when the specified timeout expires.
.sp
.LP
The \fBpthread_mutex_reltimedlock_np()\fR function is identical to the
\fBpthread_mutex_timedlock()\fR function, except that the timeout is specified
as a relative time interval.
.sp
.LP
For \fBpthread_mutex_timedlock()\fR, the timeout expires when the absolute time
specified by \fIabs_timeout\fR passes, as measured by the clock on which
timeouts are based (that is, when the value of that clock equals or exceeds
\fIabs_timeout\fR), or if the absolute time specified by \fIabs_timeout\fR has
already been passed at the time of the call.
.sp
.LP
For \fBpthread_mutex_reltimedlock_np()\fR, the timeout expires when the time
interval specified by \fIrel_timeout\fR passes, as measured by the
\fBCLOCK_REALTIME\fR clock, or if the time interval specified by
\fIrel_timeout\fR is negative at the time of the call.
.sp
.LP
The resolution of the timeout is the resolution of the \fBCLOCK_REALTIME\fR
clock. The \fBtimespec\fR data type is defined in the \fB<time.h>\fRheader.
.sp
.LP
Under no circumstance will either function fail with a timeout if the mutex can
be locked immediately. The validity of the \fItimeout\fR parameter is not
checked if the mutex can be locked immediately.
.sp
.LP
As a consequence of the priority inheritance rules (for mutexes initialized
with the \fBPRIO_INHERIT\fR protocol), if a timed mutex wait is terminated
because its timeout expires, the priority of the owner of the mutex is adjusted
as necessary to reflect the fact that this thread is no longer among the
threads waiting for the mutex.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, the \fBpthread_mutex_timedlock()\fR and
\fBpthread_mutex_reltimedlock_np()\fR functions return 0. Otherwise, an error
number is returned to indicate the error.
.SH ERRORS
.sp
.LP
The \fBpthread_mutex_timedlock()\fR and \fBpthread_mutex_reltimedlock_np()\fR
functions will fail for the same reasons as \fBpthread_mutex_lock\fR(3C). In
addition, they will fail if:
.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 13n
The caller would have blocked and the \fItimeout\fR parameter specified a
nanoseconds field value less than zero or greater than or equal to 1,000
million.
.RE

.sp
.ne 2
.na
\fB\fBETIMEDOUT\fR\fR
.ad
.RS 13n
The mutex could not be locked before the specified \fItimeout\fR expired.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	See below.
_
MT-Level	MT-Safe
.TE

.sp
.LP
The \fBpthread_mutex_timedlock()\fR is Standard. The
\fBpthread_mutex_reltimedlock_np()\fR function is Stable.
.SH SEE ALSO
.sp
.LP
.BR time (2),
.BR pthread_mutex_destroy (3C),
.BR pthread_mutex_lock (3C),
.BR pthread_mutex_trylock (3C),
.BR attributes (7),
.BR standards (7)
